We investigated the pH dependence of Eu3+ emissions from Eu 3+-intercalated layered titanium oxide (Eu/TiO) and evaluated the local structure of the intercalated Eu3+ at varying pH values using lifetime measurements and EXAFS. A red Eu3+ emission was observed under radiation by Uv light with a higher energy than the band gap of the host TiOx layer. The emission is based on energy transfer from the host TiOx layer to Eu3+. The emission intensity of Eu/TiO in 0.01 M NaOH aqueous solution was stronger than that in 0.01 M HCl aqueous solution, and the emission response of the Eu/TiO film was relatively stable to pH cycling. Two phenomena may provide a mechanism for the change in emission from Eu/TiO. One is a change in the efficiency of energy transfer from the TiOx nanosheet to Eu3+, and the other is a fine hydration state change of Eu3+ without a change in the total water amount.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films